1. Field of the Invention
The present invention relates to an inductive head for use in magnetic recording.
2. Description of the Related Art
With increasing recording density of magnetic disk apparatuses, magnetic recording media enhance the coercivity, and the track width of inductive heads for use in recording is made smaller. In addition, as the coercivity of the magnetic recording media is made higher, the thickness of the inductive heads is increased in order to provide a magnetic flux enough for recording. At present, the thickness of the front end of an upper magnetic core of the inductive heads is increased as compared with the track width, thereby making it more difficult to manufacture them.
In order to solve the problems, Japanese Un-examined Patent Publication No. Hei 7(95)-296328 describes the structure of an inductive head having a trench with a smaller width than the width of the magnetic pole end of the upper magnetic core of the inductive head, and the width of the trench is defining a track width.
As described above, in the inductive head described in Japanese Un-examined Patent Publication No. Hei 7(95)-296328, the width of the magnetic pole end of the upper magnetic core is larger than the magnetic pole tip layer defining the track width. This structure can maintain the large magnetic flux on the front end of the upper magnetic core, so as to manufacture a magnetic pole tip layer having a small thickness and a track width with high precision. However, a large magnetic field is leaked not only from the magnetic gap portion but also from the front end portion of the upper magnetic core. At recording, the recording magnetic field is applied to the recording media in a region wider than a track width desired, thereby damaging adjacent information.
As one of means of solving the problem, in order to reduce the magnetic field leaked from the magnetic pole end portion of the upper magnetic core, the upper magnetic core is constructed such that the magnetic pole end surface thereof is recessed from the air bearing surface. However, in this case, as the magnetic field leaked is reduced, the recording magnetic field is small.